1. Field of the Invention
The present invention relates to a thermoelectric conversion component, and more particularly, to a thermoelectric conversion component in which an output signal from a thermoelectric pattern is subjected to temperature compensation.
2. Description of the Related Art
As the background of the present invention, a conventional thermoelectric conversion component is disclosed in, for example, Japanese Patent No. 2526247 and Japanese Unexamined Utility Model Application Publication No. 3-117739.
FIG. 5 is a plan view of a conventional thermoelectric conversion component disclosed in Japanese Patent No. 2526247. In a thermoelectric conversion component 1 shown in FIG. 5, a thermosensitive resistor pattern 4 for temperature compensation is formed at the corner of a substrate 2 at a distance from a thermoelectric pattern 3.
FIGS. 6 and 7 are a plan view and a front view, respectively, of a conventional thermoelectric conversion component disclosed in Japanese Unexamined Utility Model Application Publication No. 3-117739. In a thermoelectric conversion component 1 shown in FIGS. 6 and 7, a thermosensitive resistor pattern 4 for temperature compensation is formed between a substrate 2 and cold junctions of a thermoelectric pattern 3. An insulating film 5 is interposed between the cold junctions of the thermoelectric pattern 3 and the thermosensitive resistor pattern 4.
In the thermoelectric conversion component 1 shown in FIG. 5, since the output from the thermoelectric pattern 3 varies with the temperatures of the cold junctions of the thermoelectric pattern 3, it is necessary to precisely detect the temperatures of the cold junctions in order to precisely measure an absolute temperature. Since the thermosensitive resistor pattern 4 for temperature compensation is formed at the corner of the substrate 2, however, when the temperature distribution of the substrate 2 is not uniform, the temperatures of the cold junctions cannot be detected precisely. This makes precise temperature compensation impossible, and leads to an increase in errors.
In the thermoelectric conversion component 1 shown in FIGS. 6 and 7, since the thermosensitive resistor pattern 4 for temperature compensation is placed under the cold junctions of the thermoelectric pattern 3, the thermoelectric pattern 3 must cross stepped portions formed by the thermosensitive resistor pattern 4, and therefore, it is prone to breakage. The thermoelectric pattern 3 does not function properly even if it has only one break. This results in a decrease in reliability and manufacturing throughput.
Accordingly, it is a main object of the present invention to provide a thermoelectric conversion component in which the temperatures of the cold junctions of a thermoelectric pattern can be precisely measured even when the temperature distribution is not uniform, so that reliability and manufacturing throughput can be improved.
In order to achieve the above object, according to an aspect of the present invention, there is provided a thermoelectric conversion component including a small heat-capacity region, a large heat-capacity region, and a thermoelectric pattern including a hot junction provided on said small heat-capacity region and a cold junction provided on said large heat-capacity region, wherein a thermosensitive resistor pattern for detecting the temperature of the cold junction is arranged on the same plane as the thermoelectric pattern, along the outer periphery of the cold junction, and adjacent to only a portion where the cold junction is formed.
Preferably, the cold junction and the thermosensitive resistor pattern may be covered with an insulating film having a high thermal conductivity.
According to another aspect of the present invention, there is provided a thermoelectric conversion component including a small heat-capacity region, a large heat-capacity region, a thermoelectric pattern including a hot junction provided on said small heat-capacity region and a cold junction provided on said large heat-capacity region, and a protective film covering the thermoelectric pattern, wherein a thermosensitive resistor pattern for detecting the temperature of the cold junction is arranged on the protective film, along the outer periphery of the cold junction, and adjacent to only a portion where the cold junction is formed.
In the thermoelectric conversion component of the present invention, since the thermosensitive resistor pattern is formed on the outer periphery of the cold junction of the thermoelectric pattern and adjacent to only the portion where the cold junction is formed, the resistance of the thermosensitive resistor pattern reflects temperature distribution information in a manner similar to thermoelectromotive forces. For this reason, even when the temperature distribution is not uniform, it is possible to precisely detect the temperature of the cold junction, to perform precise temperature compensation, and to improve the measurement accuracy of the thermoelectric pattern.
Since the thermoelectric pattern and the thermosensitive resistor pattern are flush with each other, and do not cross the stepped portion, reliability and manufacturing throughput can be improved.
By covering the cold junction and the thermosensitive resistor pattern with the insulating film having a high thermal conductivity, the conduction of heat between the cold junction of the thermoelectric pattern and the thermosensitive resistor pattern is improved, and the temperature difference therebetween is reduced. For this reason, the thermosensitive resistor pattern can precisely detect the temperature of the cold junction, more precise temperature compensation is possible, and the measurement accuracy of the thermoelectric pattern can be further improved.
Further objects, features, and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings.